// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std::marker::PhantomData;

pub trait External {}

pub struct M<'a, 'b, 'c, T, U, V> {
    a: PhantomData<&'a ()>,
    b: PhantomData<&'b ()>,
    c: PhantomData<&'c ()>,
    d: PhantomData<T>,
    e: PhantomData<U>,
    f: PhantomData<V>,
}

impl<'a, 'b, 'c, T, U, V, W> External for (T, M<'a, 'b, 'c, Box<U>, V, W>)
where
    'b: 'a,
    T: 'a,
    U: (FnOnce(T) -> V) + 'static,
    V: Iterator<Item=T> + Clone,
    W: std::ops::Add,
    W::Output: Copy,
{}
